The first commercially attractive cellular phones or terminals were introduced in the market at the end of the 1980's. Since then, a lot of effort has been made in making smaller radio communication terminals, with much help from the miniaturisation of electronic components and the development of more efficient batteries. Today, numerous manufacturers offer pocket-sized radio communication terminals with a wide variety of capabilities and services.
In order to attract customers the terminal manufacturers have therefore taken further measures to strengthen their position in the competition. Size and cost is getting more and more essential in mobile handsets design. The marked trend is that mobile handsets are getting thinner.
Another market trend is that the shell of the mobile handset is divided into an upper and lower casing. The upper casing is connected to and movable in one dimension in relation to the lower casing via a slider mechanism.
The slider mechanism comprises a slider that is slidable connected to a base. The slider is connected to the upper casing and the base is connected to the lower casing. A spring member is in one end connected to the slider and in the other end connected to the base. When the mobile handset is arranged in its closed position, the spring member presses the slider away from the base and locks the upper casing on top of the lower casing. To arrange the mobile handset in its open position, the upper casing is slidable moved in relation to the lower casing. The slider is moved towards the base and the spring member is compressed and rotated around its connection to the base. As the upper casing is moved further, the first end of the spring member has been moved passed the second end of the spring member. The spring member is now able to expand and to press the slider away from the base in an opposite direction compared to the closed position. The mobile handset is now arranged in its open position.
One known problem with prior art is that the slider mechanism takes up a lot of space as it is moved between the open and closed position.